SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4986f348a5e77f054245c5e7b634970ac269d20b13e80aabe7ac4acd1cb1492' 
  AND token = 'sy5JQ6qtqZlPp1zDAk2trhMglpJZJJsRpcCMvPBywlE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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