SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85c59b8b11206ff0bf45219f785c0c62223cbfd14f39894c80b210819bbbe4c9' 
  AND token = 'EjZopjhpuIyHs1TDnlhYTFOMOyB641beUqnagVPqgDY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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