SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e10c3e9a86a2b90e2b5490bac6ff95fb95b32c9d430e920bb44bb289f74796e' 
  AND token = 'dLbSxsY5xIOnXIRFY7qTyJFOs2JDTY1lxW4rv2C3WIA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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