SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0005860c59426f404d749458a0a69e4e607d0a42863eaae5569377c543823bd' 
  AND token = 'TXBMzxj66PQsSkvks06RKHAlNGlqnN6PWQRqs+Rs27A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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