SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ba58b6a5ff03934df9867954f90799e9740afa0be1a94810c64606c4b536cc2' 
  AND token = 'unPVjfrNyNhTtllptdVSYCaB3WWguEf6t88Q2uZvDUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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