SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a587a7c721d0f3eb6181fe54cfa034fd63a867f0bccfd3c20245f55932ee968' 
  AND token = 'lAEiAp6pZ2KeJRPPNGK5PEENoPJ5M1WltgdV/5OCSD0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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