SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc18e0b79bda0310aa6c78f2917f2d21f6eb73770683ea1aad186818a29040a1' 
  AND token = 'snvYHqRm3e4uaq5eR3zqFI/LhBZuNGhllrYgNE4A/aA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}