SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e128216197823475b41fb00d40cdc7a7893e2f3a9ffe4d17b70c73161737cb18' 
  AND token = 'iM89V5480xGdb8C5xfdmWwWXdxd8nb1Wif6/Nuus33w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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