SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7753577cc85673dfbe7d7bf3f457a9a23dbf267034bb8068fe2a51181dea8010' 
  AND token = 'pb7HxEPqghMaYka/PjCH2xfmlPUMBfFkDs7NqdKAMb0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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