SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bccbd2e082e2f9e14666083b231e58fbbdef1d78fcca501aa206dee89fb32609' 
  AND token = 'rSIDlR2C4BWoyf+V1gexRs4k7ANB+IBxsyrXUAjEfvc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}