SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a427cf247d764af88b07d2550534da64e4ac8b4b32122cd70e7625ce7467701b' 
  AND token = 'ozGrQjrGLU6z0IqOsemwhiL8B8U0OpUCbpxfLGCYmd8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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