SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9a68c8fdfe4dbd8b76993311b042195ed9120c1655ceb56eb8185277a3513bb' 
  AND token = 'A0H1oUdc+kI4szGtnm5+STYtLF1uYWMyYVw2u9f0dSE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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