SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3721e841eb190d8dab5f13421b3154aeb35af054fd6fa2db840528939ba7106' 
  AND token = 'vSthchw2SKmIBvYFY45aB1y3e6jAoq0HPyjKq26k/+U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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