SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f3d68f6e545491197e992e37c1824b4707f423554b89eaa486b39cad7042080' 
  AND token = 'gKX4VhTqyofFg9Bb/ql7YKaupmoUlBFIamGRsskqT9Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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