SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfa3bc52a517babd563655d8b55ef91e71d40c8096bcc1300032778a32cf235d' 
  AND token = 'CObOoKOFPFXTN/cR/6aFmDLepHI+EEuiVtClFpZYZG4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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