SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '127b12b51062bda2bcfa921c11d351ac21498b4625c86b4e7d77bee0b23fa352' 
  AND token = 'YdVyriGmYUluljV3azDYJWU1Vvy1MVD2/kr5JElq8zQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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