SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75956660c9559808cfef9a85204c12748ff9a82845d782ac27297330af77992c' 
  AND token = 'p/gSd6yJ5h9pVQzkY8Ny2BCWBGLQt92akHa64BgqpZc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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