SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02ccb2409134bbffb0ade3731dc4452874693cc951f6afa8bf350436d8985954' 
  AND token = 'rXVLOXZwaPLI5tIRXm6EvW8czTLEorie+VGxILHWZ8o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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