SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '560c45ed7c30491d9e0310cd4bd3d2540314b4efb463e196b269bdd88569f192' 
  AND token = '8Y8i7fkFGRbTRqkmtuNWQML3VrOiZyrg7u64u4XOQwQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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