SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b98f88727b0126354f76a4c16c193b6e6567822eae415e6fac2348391b2429d9' 
  AND token = 'Bv88ukwukziWAgHCyeJvJj8PsxHThKKvtGQ1n1khqeI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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