SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '75bfb7c76c62d0b7882385511f3937477ff45217bfec76e254f8e821640961ac' 
  AND token = 'BStAqn94OyT6Qh66Y5o59OVmSjNTyvApfa/ZjmYdoG0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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