SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '454eae22aa473cb229e794e800ddb9e27ac0d8758c1075df2494b95abec90201' 
  AND token = 'RPkqHJqFiFtAZPAkcQTLxgX1w4A1lgd2LbBUE+OmNJk=' 
  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"
    }
  }
}