SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3fb75d7afffb817a4f417648abac158c6218c9dc840402120d67683bab19bc2c' 
  AND token = 'd1Nj5xx5ULGCbMm9e2YqJ9BfmzhkL2CZaibl6LD80eE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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