SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a0a3e5e01138460df604c80822cb51cbe18bf6c4b9de756495c7aa5715a0e547' 
  AND token = 'oRz34R2Hk871VJAdbPIDVgotIuikkD9P3WqczcbQwUQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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