SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c66c963c74ce02e6398c46a7c3a2882cc9398bb94f77f92cb80c135357dc3008' 
  AND token = 'rDWO0VDrRNl8d11E3FAZEYVcN4yvyrm5Iqy+VTDNYpc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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