SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6bd0dd209e00d1cff009f7c5ff6443ec83252a646af2004f935f6414dde31c6b' 
  AND token = 'Hbbn7/6H6dEVzZsiDiSARwPoCpSVjpeQT6BXZ2wGfgs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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