SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b24ad0f04ff14d2f0e9a0095d27d4bb7a1552c90f8f3fdf386447910746b7a55' 
  AND token = 'WKbJOQ7kjreo92gEHTmpcU9RGpCRtRAhwPV0uYHiALs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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