SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '447fb240b3becda16e52eb1866e84983953ce3e2e0980bda82848072ed8c9c1a' 
  AND token = 'HUPjLfF3zN4XrfLarJ50Ja60G917x+vAuBnfSe2UuD0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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