SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b9b62665d55a80423423408f59d4b7130d65312c8c8e811acdc70b3d75614e3' 
  AND token = 'l/xHKKlucb+3+YGXM+4fQqu1YORP1GnuCXSopPhzYsc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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