SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ae37f168ac09a5a8ca71909de79029bfde981e86397c837267a01262500a533b' 
  AND token = '/9WM0QPurp1BhKVmAEZydZETeS3muxv3yswKd5J183E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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