SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6282153bb1aaac3cf2027a1475392fe3058d8a0300a5855316f867d6943f8800' 
  AND token = 'q9ajo/dXLm2ErQtLQCORXIo8ADYDCP1iVxjC3E3HD5Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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