SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd7ab2f5e7b452629de5a6e2b8480bf7fd192355cd88d91c176ba1acfdf86cb2' 
  AND token = 'INF643MULtnu5ZQUSyvv4I1o35xnLZn7Wpi14Ir1/a4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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