SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7ec15acc1370f1a207156c68551fa87cef574499e585758053e07d63905c3f3' 
  AND token = 'tuBBJ3BgIE/coCf3tumVfFv4yThxrlaz60FNmxVLMnk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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