SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '49da20739c218ef1d2ba089c0d65c5f8b4e9d4f434dbb33b8ff92940aa6e81ae' 
  AND token = 'CbC+TSIZDL5jRJATFRQU32YlzRDnsFi5AQFMOKV87Yo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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