SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f4d07ad75d86243afb12dc937cbd14c5c10c99c2cdd52f965208d3fe82da68c' 
  AND token = 'eYbEb91ESdPq6OErzLHH81GTeIdwyrzI06Wn0QfuSrM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}