SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df7586dfcd140e84037ccd02de57da0bdccc8f28f4e71f01d4e931fcb4e0625d' 
  AND token = 'AelntnaM+F4fA/IAtvepF60kb0UIB8Axmhp6jPSotG0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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