SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f926a5b54980ecc83c2ef98ec94ae6c45305cd1bf89595ae1db6551dce12346a' 
  AND token = 'ddSG6UvX1jeDxO0QqO3+ozZ+NI8eum+S9/N4a+yxvX0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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