SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b8f9d15af6ef94e51615b49e5fd928e4664b2acd4d19b8a64e6777f08b187b23' 
  AND token = 'Lcm4MV8jMJmtAHolzhlGiXWx2NWloDBLnQ2Dz8/x4r0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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