SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ad6c7422b60617f86292df642189cd8d94771879c3cccfdf38a8d9fe6b7ec8a' 
  AND token = 'bEBDanNdUbp5dI02HmAz4aO7HbjfniRWjn7HUPvLpLg=' 
  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"
    }
  }
}