SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35fc32ffd7f0a0b36696041e19f656fb0a1589d99ded67e9e985e06e4cf2734a' 
  AND token = 'FVNtTyTU59Idns5wS4W7ojHCe1Fu1FhROdcohUdfW9A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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