SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1cb8b4e841658aae944a83a878729c34cc5d0f4595861cc4db836cc19f4e142c' 
  AND token = 'CpcOYJNsQwUoB1gBpTIRtjqlArIbWm4jXAK4rl6kurM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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