SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e0e96b8572e798e74b4525086504262b4d3af668da082e4331b9a918120a8328' 
  AND token = 'JWyu/BGKrywtdight0wt/0ReL2hyqBvsUGLdW+cBC9o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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