SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6acc272ae90a473289df245c04b311e1b020b84e2ecd3f624bdf061ff76750b' 
  AND token = 'Ms1qAIS3XiCMoZJ0ckcUPSlYyfXOlyYNzb5NB4vIuR4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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