SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c12ec0cd547b365f324059138e0e402a14f3fded422f5e70f46174c6aa0e2135' 
  AND token = 'nCXHG4fRLUE6+OhxIHbL1tFViL3gKHNR4laIlAIgdL8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}